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We have obtained long-slit observations in the optical and near infrared of 12 circumnuclear HII regions (CNSFR) in the early type spiral galaxies NGC 2903, NGC 3351 and NGC 3504 with the aim of deriving their chemical abundances. Only for one of the regions, the [SIII] $lambda$ 6312 AA was detected providing, together with the nebular [SIII] lines at $lambdalambda$ 9069, 9532 AA, a value of the electron temperature of T$_e$([SIII])= 8400$^{+ 4650}_{-1250}$K. A semi-empirical method for the derivation of abundances in the high metallicity regime is presented. We obtain abundances which are comparable to those found in high metallicity disc HII regions from direct measurements of electron temperatures and consistent with solar values within the errors. The region with the highest oxygen abundance is R3+R4 in NGC 3504, 12+log(O/H) = 8.85, about 1.5 solar if the solar oxygen abundance is set at the value derived by Asplund et al. (2005), 12+log(O/H)$_{odot}$ = 8.66$pm$0.05. Region R7 in NGC 3351 has the lowest oxygen abundance of the sample, about 0.6 times solar. In all the observed CNSFR the O/H abundance is dominated by the O$^+$/H$^+$ contribution, as is also the case for high metallicity disc HII regions. For our observed regions, however, also the S$^+$/S$^{2+}$ ratio is larger than one, contrary to what is found in high metallicity disc HII regions for which, in general, the sulphur abundances are dominated by S$^{2+}$/H$^+$...
(Abbr.) A study of cicumnuclear star-forming regions (CNSFRs) in several early type spirals has been made in order to investigate their main properties: stellar and gas kinematics, dynamical masses, ionising stellar masses, chemical abundances and ot
We present the measurements of gas and stellar velocity dispersions in 17 circumnuclear star-forming regions (CNSFRs) and the nuclei of three barred spiral galaxies: NGC2903, NGC3310 and NGC3351 from high dispersion spectra. The stellar dispersions h
Circumnuclear star forming regions, also called hotspots, are often found in the inner regions of some spiral galaxies where intense processes of star formation are taking place. In the UV, massive stars dominate the observed circumnuclear emission e
We observationally study the current star formation activities of early type spiral galaxies. We construct a complete sample of 15 early type spirals having far-infrared (FIR) to optical B band luminosity ratios, L(FIR)/L(B), larger than the average
We consider the circumnuclear regions of MaNGA galaxies. The spectra are classified as AGN-like, HII-region-like (or SF-like), and intermediate (INT) spectra according to their positions on the BPT diagram. There are the following four configurations